kudzu is now deprecated, so we want to move away from it asap. hardware.py uses a file created by kudzu and left in /etc/sysconfig to glean information about the system's hardware, which it then formats in some dicts and fires up to RHN. Instead, this should use HAL to get a list of all the hardware. The format that the information is put in to be sent up to RHN should be the same as with kudzu. mayaswell do this work in the RELEASE-4.9 branch (client/up2date/rhn-client-tools/hardware.py). Part of that code has already been ported to HAL.
Should be good to go now in RHEL 5. For testing, just ensure that the hardware data visible in the webUI is similar to what pre-rhel5 clients would have sent up.